As computers have grown increasingly important in today's society, so has the importance of computers in process control systems. Process control systems control and monitor the operation of valves, actuators, transmitters, flowmeters, and other process control and monitoring devices.
Factories and other production plants are commonly used to create a variety of products. Process control systems, such as those provided by Emerson Process Management, LLP, of Austin, Tex., are widely used in such factories and/or plants in which products are manufactured or processes are controlled (e.g., chemical manufacturing, power plant control, etc.). Process control systems are also used in the harvesting of natural resources such as, for example, oil and gas drilling and handling processes, etc. Virtually any manufacturing process, resource harvesting process, etc. can be automated through the application of one or more process control systems.
Another common manufacturing process controlled by process control systems is a batch process. Batch processing typically involves recipes for creating materials. For example, batch processing is commonly used in the pharmaceutical and chemical industries to manufacture drugs and other substances. The recipe describing a batch process typically indicates how to make the desired substance. For example, a particular pharmaceutical may be created by first mixing two chemicals and then heating the mixture. The total recipe may contain hundreds of steps for creating just one substance. The recipe may indicate what materials to use and in what proportions, whether to heat or cool the materials and what equipment is needed to produce the desired substance.
Batch processing often involves managing the use of devices at a plant as the recipes are being executed. The complexity of managing such systems has traditionally prevented the process control system from globally managing all of the devices involved in performing the recipes as the large number of devices can overload the processing capabilities of the process control system.